1. Field of the Invention
The pig has been used as an experimental model to study the ontogeny of fetal immune response because of its six-layered epitheliochorial placeta which prevents the passage of maternal immunoglobulins (Ig's) into the fetus and provides for an environment that is relatively sheltered from other exogenous antigens. Positive methods of detecting Ig's in the serum or other body fluids and Ig-containing cells in the tissues are paramount to such studies.
Immunoglobulin detection also holds considerable potential in porcine medicine. Immunoglobulin M (IgM) is the first and main Ig produced in an early primary immune response. Identification and quantitation of IgM could therefore be useful as a diagnostic technique for differentiating current from past infection. Immunoglobulin A (IgA) is the main Ig in secretions and excretions and plays an important role in secretory immunity especially to respiratory and enteric infectious agents.
The methods involved in these applications require monospecific antisera to Ig heavy chains at a level of specificity which heretofore has seldom been achieved in conventional preparations. For example, most preparations of purified IgM are commonly contaminated with trace amounts of .alpha..sub.2 -macroglobulins and antisera prepared to such IgM preparations contain antibodies to .alpha..sub.2 -macroglobulins. These antibodies are difficult to eliminate and tend to interfere with IgM detection even at very low concentrations. To obtain antisera to procine IgM free of antibodies to both .alpha..sub.2 -macroglobulins and Ig light chains, it is necessary to extensively absorb the preparations with fetal-porcine serum devoid of Ig's and with heterologous Ig's.
This invention relates to the application of hybridoma technology to the preparation of cell lines capable of producing monoclonal antibodies (Mabs) to porcine Ig's having a high degree of heavy-chain specificity.
2. Description of the Prior Art
Fused cell hybrids of mouse myeloma cells with antibody-producing splenocytes have been widely utilized in recent years to produce Mabs to a variety of agents including, for example, viruses, antigens, cell-associated antigens, blood cells, enzymes, and other proteins. Illustrative of these are the array of hybrid cell lines for producing monospecific antibodies to cell-associated antigens disclosed by Kung et al. in U.S. Pat. Nos. 4,361,449, 4,361,550, and 4,364,932-'937. As another example of this technology, Wands et al., U.S. Pat. No. 4,271,145, fuses BALB/c mouse myeloma cells with BALB/c lymphocytes to yield hybridoma cell lines which secrete highly specific IgG or IgM Mabs to hepatitis virus antigen.
It is apparent from the discussion in the "Field of the Invention" that antibody to porcine Ig's having the specificity achieved by the Mabs of the prior art would be an advantageous tool to both immunological research and porcine diagnostic medicine.